Stockholders' Equity - Stock Options and a Summary of Activity (Details)	9 Months Ended
	Sep. 30, 2021 $ / shares shares
Number of Options
Outstanding at beginning of period (in shares) | shares	221,450
Granted (in shares) | shares	76,900
Canceled/forfeited (in shares) | shares	(35,287)
Expired (in shares) | shares	(1,500)
Outstanding at end of period (in shares) | shares	257,338
Vested and expected to vest at period end (in shares) | shares	218,795
Exercisable at period end (in shares) | shares	78,156
Weighted Average Exercise Price Per Share
Outstanding at beginning of period (USD per share) | $ / shares	$ 3.45
Granted (USD per share) | $ / shares	5.39
Canceled/forfeited (USD per share) | $ / shares	5.43
Expired (USD per share) | $ / shares	53.50
Outstanding at end of period (USD per share) | $ / shares	3.49
Vested and expected to vest at period end (USD per share) | $ / shares	3.43
Exercisable at period end (USD per share) | $ / shares	$ 3.48
Weighted Average Remaining Contractual Life (in years)
Outstanding at end of period	8 years 4 months 24 days
Vested and expected to vest at period end	8 years 3 months 18 days
Exercisable at period end	7 years 9 months 18 days